a case study of Doi Chang village, Chiang Rai, Thailand Suriyachai Chaisuriya creator Chao, Kuo Chieh Chairperson Suttisak Soralump Co-chairperson Avirut Puttiwongrak Examination Committee Royal Thai Government Fellowship Scholarship Donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2025 continuing eng

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283 leaves : ill.+ 1 online resource Groundwater fluctuations are a major factor in slope instability and landslide initiation, especially in mountainous terrains with complex hydrogeological settings. However, the mechanisms by which fluctuating groundwater levels influence slope failure are not yet fully understood. This study aims to investigate the relationship between groundwater fluctuations and landslide occurrence by applying 3D geological modeling and groundwater modeling. The research focuses on a case study in a landslide-prone area in Doi Chang Village, Chiang Rai Province, Thailand.A detailed geological and hydrogeological investigation incorporated field mapping, borehole logging, electrical resistivity imaging, and soil laboratory testing. Based on these datasets, a 3D Engineering Geological Model was constructed to represent the subsurface conditions accurately. These models were then used to develop a numerical groundwater flow model using the MODFLOW model to simulate groundwater responses under variable rainfall recharge scenarios.The results demonstrate a strong correlation between rising groundwater levels and increased pore water pressure within the shallow colluvial layer, reducing effective stress and potential slope failure. Model calibration and validation against observed groundwater level data confirmed the reliability of the simulation. Prediction analyses further revealed that a 20% increase in rainfall could elevate groundwater to critical thresholds. In contrast, scenarios with subsurface drainage showed significant groundwater drawdown, indicating their effectiveness in mitigating landslide risk.This study contributes to a better understanding of groundwater-induced slope failure. It highlights the utility of integrating 3D geological modeling with groundwater model simulations in landslide hazard assessment and mitigation planning. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geotechnical and Earth Resources Engineering Thesis (M. Sc.) - Asian Institute of Technology, 2025 Landslide hazard analysis Data processing Thailand Chiang Rai Groundwater Thailand Chiang Rai Geological modeling Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B23572 http://203.159.5.9/ait-thesis/detail.php?q=B23572 260209 20260818112745.0